The present invention relates to the field of electrical wire continuity testing and telephone dial tone detection.
The common analog telephone line consists of two wires, a TIP wire and a RING wire. After a phone line has been installed, or when a problem with communication through existing lines arises, the lines must be checked to ensure proper functionality or to locate the source of the problem. It is common in the industry for a lineman, after installation, to use a butt set (or butt-in set) to listen for dial tone in order to verify proper operation of the line and to report line status to the office.
A butt set is essentially a portable telephone that the lineman carries, usually at his side. It commonly has clip leads so that the lineman can clip to pins in a B-box or cross-box to verify operation of the line at that point outside a building.
In this age of telecommunications, linemen often simply install a group of telephone lines to a building while other workers route the lines within the building. In addition, businesses now have their own management information systems (MIS) personnel who maintain their own internal telephone lines, as well as other computer and electrical related lines. For example, it is now common for MIS personnel or network installers to route wire for computers which could include bundles of wires containing, among others, telephone fax lines, telephone modem lines, local area network lines, wide area network lines, and printer lines. It is imperative that these lines be functional and correctly routed.
To verify proper installation of the telephone line within a building, the installer or troubleshooter connects a conventional phone or butt set to the line to verify the presence of a "dial tone". As it is becoming common for lines to have modular type receptacle connectors within the building, a breakout adapter must be connected to the modular connector so that the clip leads from the butt set can be attached. As such, then it is necessary to carry both a modular breakout adaptor along with the conventional butt set to listen for dial tone.
Quite often, an installer or troubleshooter also wants to trace wires, check continuity, or simply distinguish wires in a bundle. When this is the case, additional equipment must be used. In accordance with a known practice, an alternating electrical signal (or "tone") placed upon a particular wire at some remote location can then be detected, making it possible to identify that wire, confirm its electrical continuity, and trace its physical location. A special signal generator, sometimes called a "warbler", is used on the remote end of the particular wire to impress a high frequency signal which in audio form is easily distinguished from the telephone dial tone. At the other end of the wire a tone probe or detector may be used to identify the wire which carries that signal. In the industry, "tone" commonly refers to the high frequency warbler sound, while "dial tone" refers to the standard telephone dial tone.
Since equipment is expensive and is generally personally carried by the installer or troubleshooter, he must decide which equipment to purchase and carry, and which to leave behind, based on cost, size, and functionality. For instance, a simple continuity checker may be used, even though a tone probe is preferred and more functionally suited, simply because of cost and size concerns. In addition, the time lost locating and switching equipment could be used more productively. Furthermore, unlike a lineman, computer system installers or troubleshooters neither require all the functions available in a butt set to successfully complete their task nor would they prefer to carry a butt set and modular breakout adaptor if a better equipment is available.
The present invention, therefore, is based upon our recognition that there is a need for a more cost efficient, easy to use, and easily portable alternative to existing equipment.